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Matt Greig and Philip Nagy

Context:

Epidemiological studies highlight a prevalence of lumbar vertebrae injuries in cricket fast bowlers, with governing bodies implementing rules to reduce exposure. Analysis typically requires complex and laboratory-based biomechanical analyses, lacking ecological validity. Developments in GPS microtechnologies facilitate on-field measures of mechanical intensity, facilitating screening toward prevention and rehabilitation.

Objective:

To examine the efficacy of using GPS-mounted triaxial accelerometers to quantify accumulated body load and to investigate the effect of GPS-unit placement in relation to epidemiological observations.

Design:

Repeated measures, field-based.

Setting:

Regulation cricket pitch.

Participants:

10 male injury-free participants recruited from a cricket academy (18.1 ± 0.6 y).

Intervention:

Each participant was fitted with 2 GPS units placed at the cervicothoracic and lumbar spines to measure triaxial acceleration (100 Hz). Participants were instructed to deliver a 7-over spell of fast bowling, as dictated by governing-body guidelines.

Main Outcome Measures:

Triaxial total accumulated body and the relative uniaxial contributions were calculated for each over.

Results:

There was no significant main effect for overs bowled, in either total load or the triaxial contributions to total load. This finding suggests no cumulative fatigue effect across the 10-over spell. However, there was a significant main effect for GPS-unit location, with the lumbar unit exposed to significantly greater load than the cervicothoracic unit in each of the triaxial planes.

Conclusions:

There was no evidence to suggest that accumulated load significantly increased as a result of spell duration. In this respect the governing-body guidelines for this age group can be considered safe, or potentially even conservative. However, the observation of higher body load at the lumbar spine than at the cervicothoracic spine supports epidemiological observations of injury incidence. GPS microtechnologies might therefore be considered in screening and monitoring of players toward injury prevention and/or during rehabilitation.

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Matthew J. Cross, Sean Williams, Grant Trewartha, Simon P.T. Kemp and Keith A. Stokes

Purpose:

To explore the association between in-season training-load (TL) measures and injury risk in professional rugby union players.

Methods:

This was a 1-season prospective cohort study of 173 professional rugby union players from 4 English Premiership teams. TL (duration × session-RPE) and time-loss injuries were recorded for all players for all pitch- and gym-based sessions. Generalized estimating equations were used to model the association between in-season TL measures and injury in the subsequent week.

Results:

Injury risk increased linearly with 1-wk loads and week-to-week changes in loads, with a 2-SD increase in these variables (1245 AU and 1069 AU, respectively) associated with odds ratios of 1.68 (95% CI 1.05–2.68) and 1.58 (95% CI 0.98–2.54). When compared with the reference group (<3684 AU), a significant nonlinear effect was evident for 4-wk cumulative loads, with a likely beneficial reduction in injury risk associated with intermediate loads of 5932–8651 AU (OR 0.55, 95% CI 0.22–1.38) (this range equates to around 4 wk of average in-season TL) and a likely harmful effect evident for higher loads of >8651 AU (OR 1.39, 95% CI 0.98–1.98).

Conclusions:

Players had an increased risk of injury if they had high 1-wk cumulative loads (1245 AU) or large week-to-week changes in TL (1069 AU). In addition, a U-shaped relationship was observed for 4-wk cumulative loads, with an apparent increase in risk associated with higher loads (>8651 AU). These measures should therefore be monitored to inform injury-risk-reduction strategies.

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John Andrew Badagliacco and Andrew Karduna

Baseball pitching is one of the most dynamic biomechanical tasks performed by athletes. At the college and professional level, the shoulder can experience velocities in excess of 7000°/s in internal rotation. 1 Given the repetitive nature of this loading, it is perhaps not surprising that injuries

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Joseph J. Crisco, Nikolas J. Osvalds and Michael J. Rainbow

square retroreflective markers (13 × 13 mm). Testing was held indoors at the Brown University Athletic Center (Providence, RI) over a 2-day session. A portable batting cage was assembled (15.2 × 3.0 × 4.3 m) on the gymnasium floor. A pitching machine (Iron Mike MP5; Master Pitching Machine, Kansas City

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Paul S. Bradley and Jack D. Ade

parallel to the player on the ball.  Push-up pitch Player moves up the pitch to support the play (defensive and middle third of the pitch only).  Run the channel Player runs with or without the ball down to one of the external areas of the pitch.  Run-in behind Player aims to beat the opposition offside

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Anat V. Lubetzky, Bryan D. Hujsak, Gene Fu and Ken Perlin

the pitch, roll, and yaw directions typically required a three-dimensional video motion capture system with high-resolution cameras and multiple infrared markers. Such systems have provided accurate information on head movement patterns in patients with vestibular dysfunction ( Lang et al., 2013

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Gretchen D. Oliver, Jessica K. Washington, Sarah S. Gascon, Hillary A. Plummer, Rafael F. Escamilla and James R. Andrews

is accomplished by the sequential activation of LPHC musculature, 37  thus changes in muscle performance may alter kinematics up the kinetic chain. The current results are similar to previous literature that has examined the effects of baseball pitchers throwing a simulated game 38 – 41 on pitching

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Salman Nazary-Moghadam, Mahyar Salavati, Ali Esteki, Behnam Akhbari, Sohrab Keyhani and Afsaneh Zeinalzadeh

Stroop task. The auditory Stroop task consisted of a series of stimuli consisting of “high” or “low” words spoken in Persian presented with either high-pitched or low-pitched voice, resulting in 2 types of stimuli, that is, congruent stimuli where the word and the vocalization pitch matched and

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Yusuf Köklü, Utku Alemdaroğlu, Hamit Cihan and Del P. Wong

number of different factors which may affect exercise intensity. These factors include the number of players and the pitch size, 5 – 8 the game rules, 9 – 12 coach encouragement, 13 the absence or presence of goalkeepers, 14 , 15 team formation, 16 and training regime. 17 – 19 In addition to these

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Corbin A. Hedt, S. Brett Holland, Bradley S. Lambert, Joshua D. Harris and Patrick C. McCulloch

. Biomechanical comparison of baseball pitching and long-toss: implications for training and rehabilitation . J Orthop Sports Phys Ther . 2011 ; 41 ( 5 ): 296 – 303 . PubMed ID: 21212502 doi:10.2519/jospt.2011.3568 10.2519/jospt.2011.3568 21212502 19. Slenker NR , Limpisvasti O , Mohr K , Aguinaldo